This proposal uses ecological momentary assessment (EMA) methods to examine how the provision of active help to individuals with Alzheimer?s Disease and related dementias (ADRD) influences the immune system and health of ADRD caregivers. We hypothesize that caregivers who feel emotionally close to the care recipient will show improvements in immune system biomarkers, self-reported health outcomes, and health-related quality of life as their active help increases. Two hundred and fifty caregivers will be recruited from the Center of Excellence for Alzheimer?s Disease of Long Island to participate in a three-wave longitudinal study in which we will collect data at baseline, 6 months, and 12 months. We will use EMA methods to collect data on active help and the caregiving context at baseline and 6 months, and and we will assess immune system activity and self-reported health outcomes at baseline, 6 months, and 12 months. Our analyses will test whether active help is beneficially associated with makers of inflammation (e.g., Il-6/TnF alpha-receptor) and repair (e.g., SOD, progesterone) among caregivers who feel emotionally close to the recipient.